"Nostalgia is a seductive liar," said US diplomat George Ball. It's unlikely that he was referring to children's television programmes of the late 80s and early 90s, but he might as well have been.

If you grow up with a love of television, you tend to retain great fondness for the shows of your youth as the years pass. However, as you'll be aware – especially if you caught much of CITV's recent Old Skool Weekend, in which two days were given over to repeats of Fun House, Super Gran and Wizadora – much of what felt like important, high-quality broadcasting 20 years ago doesn't quite stand up to repeat viewing. Not now that the original audience for that stuff is more into morose Scandinavian dramas, baking competitions and Panorama.

How, then, to greet news that Knightmare is making a comeback? As part of YouTube's Geek Week running from 4 August, a one-off Knightmare special will feature Peep Show's Isy Suttie and actor Jessie Cave alongside Hugo Myatt, better known as Treguard, the show's original dungeon master.

Created in 1987 by producer by Tim Child (who returns for the YouTube special), Knightmare made pioneering use of blue screen – then mostly used for weather forecasts – to blend live action with hand-drawn and computer-generated imagery. It created a fantastical dungeon through which one young "dungeoneer" would shuffle around with bucket on his or her head (it's a long story) as three teammates offered guidance from afar.

It'll be interesting to see whether the 2013 Knightmare remains true to the spirit of the original. It would be all too easy to play up to the cheerful nostalgia factor that's attached itself to the show in the 19 years since it was cancelled. Watching clips of it on YouTube or repeats on Challenge, it's easy to scoff at the dated effects, the over-enthusiastic actors prancing about spouting riddles, the awkwardness of the young contestants – but that overlooks just how exciting Knightmare was to watch first time around.

Arriving in era when the 32-bit graphics of the Playstation 1 were an impossibly far-off dream, the world created in Knightmare was a genuine accomplishment – a convincing melding of live action and "virtual reality", done in a way TV has almost always managed to get wrong since.

But the biggest thing it had going for it was the amount of love that went into the show. Drawing from authors such as JRR Tolkien, Jack Vance and TH White, the creators knew that fancy special effects weren't enough – they needed to inject serious amounts of personality and humanity if they had any hope of getting their young audience to go along with all that dungeoneering, riddle-me-this, bucket-on-the-head nonsense.

The fact that it's still fondly remembered to this day, so much so that it's getting a revival, is testament to the creators' success. It should also act as a lesson to contemporary film and TV makers: you may have a mindboggling array of increasingly cheap, increasingly spectacular visual effects, but if you want to create something that will still be loved two decades on, it takes something more than technology alone can provide.